Form for making concrete slab

ABSTRACT

A form for making concrete slabs comprises a closed frame having transverse beams detachably affixed to its underside and a panel positioned on the beams within the frame and constituting the bottom of the form.

O Umted States Patent 1 1 3,595,51 7

[72] Inventors Fritz Grebner [56] References Cited a 65 Main! Rhine; UNITED STATES PATENTS f 62 1,285.11 1 6 11 1918 Singers et al 249/160 x Wreshaden; Eckhard Wink, Gelsbergslr.

2,028,443 1/1936 Dormer 25/l2l 29, 6201 Nondenstadt, all of, Germany 2 460 167 1/1949 C I 25/4] J 742396 3 009 229 11/1961 T Sen 25 121 P Filed y umey [4S] Patented July 27, 1971 Primary Examiner.l. Spencer Overholser Assistant Examiner-De Walden W. Jones Attorney-Kurt Kelman [54] FORM FOR MAKING CONCRETE SLAB 3 Claims, 4 Drawing Figs.

52 us. 01 .j 249/163, 25/ l 18 R [51] lnt.Cl .J B4lb 11/60 A STRAC A form for making concrete slabs comprises a [50] Field of Search 249/163, closed frame having transverse beams detachably afiixed to i s underside and a panel positioned on the beams within the frame and constituting the bottom of the form.

FORM FOR MAKING CONCRETE SLAB Background and Summary the Invention The present invention relates to improvements in forms for manufacturing large concrete slabs.

Conventionally, heavy and rigid steel plates resting on vibratory standards have been used for this purpose. Afterthe concrete mass has been poured and the reinforcing elements placed therein, the concrete remains in such forms until set. To shorten the setting time, use has been made of steam setting, which'not only makes the process more expensive but also necessitates production in the factory.

It is the object of this invention to produce concrete slabs with more ease and less cost by making it possible to reuse portions of the form for the production of a subsequent slab shortly after the form has been filled with the concrete mass and, if desired, vibrated but before the concrete is completely set.

This object is accomplished in accordance with the invention with a form which comprises a closed frame defining the edges of the concrete slab to be made in the form, a plurality of transverse beams detachably affixed to the underside of the frame, and a panel positioned on the beams within the frame and constituting the bottom of the form.

In such a form, the bottom panel of the form need not be completely rigid since it is supported on the transverse beams of the frame. Thus, it may be made, for instance, of relatively thin-gaged sheet metal, plywood or plastic sheeting and the like.

According to one feature of the invention, suitable vibrators may be mounted in the frame, and after the concrete has been poured and vibrated, the transverse support beams for the panel may be detached from the frame, the frame may be lifted, and the slab may be permitted to set on the bottom panel in stacks of thusly made concrete slabs. Thus, the frame and transverse beams are ready immediately for making another slab without waiting for the previously produced slab to set and without using expensive and complicated setting processes. Only a new panel is needed for each form, which is quite inexpensive compared to rigid steel plates. Furthermore, the procedure is so simple that it may be carried out at the building site, rather than in the factory.

Brief Description of Drawing The above and other objects, advantages and features of the present invention will become more apparent from the following detailed description of a preferred embodiment, taken in conjunction with the accompanying drawing wherein FIG. 1 is a partial top view of a frame forming part of this invention, including a schematic showing of the transverse beams detachably affixed to the frame;

FIG. 2 is a side view of the frame of FIG. 1;

FIG. 3 is an enlarged side view of a portion of the frame of FIG. 1, also showing stacking of the finished concrete slabs; and

FIG. 4 is an end view of the frame shown in FIG. 3.

Detailed Description Referring now to the drawing and first to FIGS. land 2, the apparatus of the invention is shown to include a rectangular frame 1 which, in the illustrated embodiment, is made of a hollow profile of square cross section (see FIG. 4) although it could be of any desired profile. A plurality of spaced transverse beams 2 are detachably affixed to the underside of the frame in a manner to be described hereinafter. A plurality of suitable vibrators 3 are mounted in the frame. To enable the frame to be transported by a crane or the like, it is provided with eyelets or lugs 5 to which supporting cables 5 are attached.

As shown in FIGS. 3 and 4, the transverse beams 2 may e readily detached from the underside of frame 1. For this urpose, pairs of brackets 7, 7 project from the underside of opposite legs of frame 1, the brackets having a horizontally extending portion 8 supporting each beam 2 and defining an opening 6 between the bracket portion and the underside of the frame. After the beams are positioned in their supporting brackets, they are held in place by pivotal latches 9. The latches are fixed to a shaft 10 pivotally journaled in bearings ll mounted on the outside of frame 1. One end of the shaft is bent into a handle 12 so that the latches 9 may be pivoted into an open and closed position, the closed position being shown in FIG. 3 and the open position being shown in broken lines in FIG. 4. Spring latches 13 and 14 are fixed to the frame to hold the shaft in its respective positions. Also, it is useful to provide the transverse beams 2 with guide rails 15, 15 for engagement with the bracket portions 8.

As can be seen in FIGS. 3 and 4, the panel 16, onto which the concrete mass is poured to form the slab within frame 1, is supported on the transverse beams 2, the concrete form thus being constituted by the panel and the frame, with the panel being the bottom of the form. In the illustrated embodiment, the panel 16 consists of plywood.

FIG. 3 illustrates how the finished slabs are stacked at the building site where they are made. In this illustration, it has been assumed that a concrete slab 17 with its lattice girder 18 has previously been made and placed at the stacking site. Wooden support beams 19 are then placed on the lattice girder of the underlying slab, and a form consisting of frame 1, transverse beams 2 and panel 16, which contains the concrete mass and has the lattice girder built into it, is superposed on the support beams 19. Stacking is preferably done in such a manner that the support beams sustain the entire weight, with the panel 16 resting on the support beams, so that the transverse beams 2 carry no load. The latches 9 are now pivoted upwardly into their open position so that the transverse beams 2 may be laterally removed from the brackets 7 through openings 6. The frame is now lifted so that the newly made concrete slab with its girder rests with panel 16 on the support beams 19 which, in turn, are supported on lattice girder 18 forming part of underlying concrete slab 17. This process may be repeated until any desired number of slabs have been tacked. In this manner, the frame with its transverse beams may be removed and reused before the concrete of each slab has completely set, and it is not necessary to use expensive setting processes for concrete in order to make economic use of the concrete forms, only the cheap bottom panels remaining tied up until final setting of the concrete.

We claim: 1. A form for making a concrete slab, comprising 1. a closed frame defining the edges of the slab to be made in the fomi, 2. a plurality of transverse beams detachably affixed to the underside of the frame, 3. pairs of brackets projecting from the underside of opposite legs of the frame, a. the brackets defining lateral openings for receiving the beams, 4. movable latch means for selectively opening and closing the openings, and 5. a panel positioned on the beams within the frame and constituting the bottom of the form. 2. The form of claim 1, further comprising guide rails on the transverse beams for engagement with the brackets.

3. The form of claim 1, further comprising vibrators mounted in the frame. 

1. A form for making a concrete slab, comprising
 1. a closed frame defining the edges of the slab to be made in the form,
 2. a plurality of transverse beams detachably affixed to the underside of the frame,
 3. pairs of brackets projecting from the underside of opposite legs of the frame, a. the brackets defining lateral openings for receiving the beams,
 4. movable latch means for selectively opening and closing the openings, and
 5. a panel positioned on the beams within the frame and constituting the bottom of the form.
 2. a plurality of transverse beams detachably affixed to the underside of the frame,
 2. The form of claim 1, further comprising guide rails on the transverse beams for engageMent with the brackets.
 3. The form of claim 1, further comprising vibrators mounted in the frame.
 3. pairs of brackets projecting from the underside of opposite legs of the frame, a. the brackets defining lateral openings for receiving the beams,
 4. movable latch means for selectively opening and closing the openings, and
 5. a panel positioned on the beams within the frame and constituting the bottom of the form. 